Malicious PDF — malware analysis report

Static analysis result for SHA-256 78c5aa03fe6c6957…

MALICIOUS

PDF

83.9 KB Created: 2021-09-07 11:04:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-03
MD5: 445340005f2b05e3379e8cc7f6d3e89a SHA-1: f10307f18786885152dd0ce84d74e717ab816eed SHA-256: 78c5aa03fe6c69570bb4a63a33123a62beae265d8dc92bb60c0688a4cfce3b18
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as a malicious PDF by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains embedded JavaScript, which is often used to execute malicious code or redirect users. The presence of multiple link farm URLs, some pointing to compromised CMS uploads, further supports its role as a distribution vector, likely for phishing or malware. The document body was unreadable, but the heuristics and URLs strongly suggest a malicious purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://chalappuram.com/userfiles/file/72466709843.pdf In PDF document text
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/f52aafaa0449e6f9a40c03be3d13e042/fisobezasijexitubuw.pdfIn PDF document text
    • https://www.zaantraining.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160cca062c815a---91619998612.pdfIn PDF document text
    • http://weighlessthisyear.com/ckfinder/userfiles/files/12793700089.pdfIn PDF document text
    • http://yishiweb.com/upfiles/files/20210730_063013.pdfIn PDF document text
    • https://www.mnspineandsport.com/wp-content/plugins/super-forms/uploads/php/files/2565014faf2803ca85e0960bb47628e1/toxeditusisupegek.pdfIn PDF document text
    • http://acsalma.hu/userfiles/files/tubexel.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/mnn4e76bpcmmmcq7c09rkim3c3/nenolijorutemisub.pdfIn PDF document text
    • https://villamishkan.com/310renonew/front/images/files/13758027928.pdfIn PDF document text
    • http://vivo-mebel.ru/upload/file/21970045160.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/41990150794.pdfIn PDF document text
    • http://novaserv.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078df5797526---lonutawodejitaxamavetut.pdfIn PDF document text
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0bd4e93bdc---jubusipupataburegirujoma.pdfIn PDF document text
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fe9c229cfb---romakezinorotog.pdfIn PDF document text
    • https://akarchlight.com/wp-content/plugins/super-forms/uploads/php/files/ac0545ed56f8df778e1974be91bdb79f/zokolatozo.pdfIn PDF document text
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095a4ac96059---sigukapot.pdfIn PDF document text
    • http://veterina-hrib.cz/user-uploads/files/19937657145.pdfIn PDF document text
    • http://gsoam.ge/wp-content/plugins/formcraft/file-upload/server/content/files/160ac161de6473---jajutazavifevozo.pdfIn PDF document text
    • http://giftboxvietthuy.com/upload/ck/files/46116160781.pdfIn PDF document text
    • https://mrmusicfoundation.org/wp-content/plugins/super-forms/uploads/php/files/0ms33kj2l7ntm9oj20h15slscr/18651667813.pdfIn PDF document text
    • http://careerpathrecruitment.com/swapscan/app/webroot/js/ckfinder/userfiles/files/rivovovuvofetorekolozuxa.pdfIn PDF document text
    • http://pngroup.pl/ckfinder/userfiles/files/34309152305.pdfIn PDF document text
    • https://bikeid.net/ckfinder/userfiles/files/bomodoxurutagonuvapifukiv.pdfIn PDF document text
    • https://whatproperty.ng/ckfinder/userfiles/files/lumew.pdfIn PDF document text
    • http://www.next-conseil.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1608cefc250ffc---nugigubapekupa.pdfIn PDF document text
    • https://mrmusicfoundation.org/wp-content/plugins/super-forms/uploads/php/files/q0022ejcnj88u5fumbmj70r2ef/sobusaxavibosokejitekuful.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=hec+university+ranking+2019+in+pakistan+pdfPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e0b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0B7 11452 bytes
SHA-256: 305fe8c3134451aacb29f2a8d1925afc5064cd6a5e38609363febad7c450e991
font_01_sfnt_off0000fbe1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBE1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000113f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113F3 17380 bytes
SHA-256: 439aeeb8132dd006753c625b93bf1a1cc0484d0bac2daff058244d245cf7d9a2