Malicious PDF — malware analysis report

Static analysis result for SHA-256 77dbcba6fda41b39…

MALICIOUS

PDF

82.6 KB Created: 2021-09-14 07:17:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: b08c79aa7ce0fb635b5f8c2df1f5917b SHA-1: b42ca2502c998c12731045a1f6f193c64336be20 SHA-256: 77dbcba6fda41b397a204f70a1a9c9e6223c8ddd76f33f249ddea2901f6c9cfe
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was identified as malicious by a machine learning classifier and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to compromised websites. These sites likely serve as landing pages for phishing attacks or to distribute further malware payloads. The presence of multiple compromised CMS upload links suggests a tactic to obscure the true origin of the malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 6

  • 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.
  • 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://www.adarshvidhyasankul.org/userfilesfile/lipatisuvo.pdf In PDF document text
    • http://www.galiantsolutions.com/emailimages/file/bebovinij.pdfIn PDF document text
    • http://aquarium-kochi.com/app/webroot/ckfinder/userfiles/files/29353204755.pdfIn PDF document text
    • http://beloezoloto.ru/userfiles/file/59192932156.pdfIn PDF document text
    • https://mimpishio2.net/contents/files/32852877305.pdfIn PDF document text
    • https://readxyz.org/wp-content/plugins/super-forms/uploads/php/files/ef43f7803969f16f56be000940ea4fbe/wibokataji.pdfIn PDF document text
    • http://provia-events.de/pics/fotos/1/file/41167861628.pdfIn PDF document text
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/161372faf288b7---84299131246.pdfIn PDF document text
    • https://volnynaklad.cz/data/file/ziguzojotekedoseduf.pdfIn PDF document text
    • https://agronlogistics.com/userfiles/files/lalewasotuferox.pdfIn PDF document text
    • https://justforjetscatering.com/userfiles/image/files/pijepoginiwakoma.pdfIn PDF document text
    • https://optimumquestsolutions.com/ckfinder/userfiles/files/358329313.pdfIn PDF document text
    • https://congchungnguyenlieu.vnpec.xyz/uploads/files/51482849873.pdfIn PDF document text
    • https://magyar-logyogyasz.hu/fileok/file/48261353824.pdfIn PDF document text
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613436281e0c1---topidebinudav.pdfIn PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/ed8fkrfhbaiattv9cvfjpo55om/75980985587.pdfIn PDF document text
    • http://gdgom.com/upload/file/210912044708916971ti24g27lh0l7.pdfIn PDF document text
    • http://smenergy.kr/uploaded/file/168842769613310691e6c5.pdfIn PDF document text
    • http://mh-gartengestaltung.de/userfiles/file/53258762962.pdfIn PDF document text
    • https://suncables.co/images/file/83217397137.pdfIn PDF document text
    • http://meghdoothsuzuki.com/uploads/37344546590.pdfIn PDF document text
    • http://richardchong.com/userfiles/files/79431351203.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=titanium+roblox+idPDF 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_off0000da82.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA82 10412 bytes
SHA-256: 9bf8fd680ca9547ceefce94a4129df5b74cbd987bc4e5a1f89ea270f152f28a1
font_01_sfnt_off0000f202.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF202 19436 bytes
SHA-256: 975b73208ef578651ea136da4b0d38899dddf774123c591461459f432bcdd73c
font_02_sfnt_off00012519.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12519 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1