Malicious PDF — malware analysis report

Static analysis result for SHA-256 8de3d67c6db18135…

MALICIOUS

PDF

93.3 KB Created: 2021-06-27 03:56:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 49a772655553ee1b396170ddf9c46765 SHA-1: a8113e00861c2a7d8f88a040a235eefbb1ef5359 SHA-256: 8de3d67c6db181358d932921b9b58b682eb375518b23399e008bcca44bb58544
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress sites and disposable domains, indicating a phishing or malware distribution campaign. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is heavily obfuscated and unreadable, but the presence of external links and the heuristic firings are sufficient to determine its likely purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9929

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 https://chcial.ru/uplcv?utm_term=direct+and+indirect+rule+in+nigeria PDF link annotation
    • http://wecans.net/_UploadFile/Images/file/golubopepa.pdfIn PDF document text
    • https://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c83ed4ed4f---73289864935.pdfIn PDF document text
    • http://recruiters-zone.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607cb86df2122---labefigon.pdfIn PDF document text
    • http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071fd1d3a0c0---38133053759.pdfIn PDF document text
    • https://wulf-sanitaer.de/wp-content/plugins/super-forms/uploads/php/files/mqdlp76unq1qjrn4ti7j61tq3h/kebivaxusufigawalakisax.pdfIn PDF document text
    • https://utilitydiscount.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b309e31eab5---bajiluxiwagonuzuka.pdfIn PDF document text
    • http://rasmesafar.net/basefile/basefiles/lifoxetagukududarediv.pdfIn PDF document text
    • http://herodumpsterrental.com/wp-content/plugins/super-forms/uploads/php/files/b27754a5d1e67437ca0f344821f067d1/64037146175.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/16095cf6e57b42---zojexama.pdfIn PDF document text
    • http://www.theagentpipeline.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095f7d55b31e---49854685233.pdfIn PDF document text
    • http://firegallery.ru/img/upload/84822931698.pdfIn PDF document text
    • http://apogeeconsultancy.com/upload/files/bapot.pdfIn PDF document text
    • https://oddluzanie.net/userfiles/file/83475000423.pdfIn PDF document text
    • https://tehnol.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16087927ab0226---50586268483.pdfIn PDF document text
    • http://jar-ted.pl/file/zezokeduririxotego.pdfIn PDF document text
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16073d26858e02---36687714358.pdfIn PDF document text
    • https://protrialse.eu/files/files/72409762609.pdfIn PDF document text
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/16094664ac4a59---fivafagesuzetobavejodobig.pdfIn PDF document text
    • http://mobilesamara.com/img/files/file/45773220391.pdfIn PDF document text
    • http://sarljarry.fr/userfiles/file/23196371008.pdfIn PDF document text
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d694adce00---81394441418.pdfIn PDF document text
    • https://www.acptechnologies.com/wp-content/plugins/formcraft/file-upload/server/content/files/160afda9595109---buvesusaliberikemiri.pdfIn PDF document text
    • https://trichynext.com/wp-content/plugins/super-forms/uploads/php/files/b8134db361ceda467229f0b934390a68/5313646089.pdfIn PDF document text
    • http://szalkasszorutacskok.hu/app/webroot/files/content/files/51621614530.pdfIn PDF document text
    • https://www.emma-solutions.de/wp-content/plugins/formcraft/file-upload/server/content/files/16093a16f229e1---jixokeduxipuxewulomigu.pdfIn PDF document text
    • 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_off00010ad4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AD4 10360 bytes
SHA-256: 501e14fe3ee7ce020bd8b14ae101654d07d2822a4ca2383292e1fd6241918985
font_01_sfnt_off0001221f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1221F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013a31.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13A31 17720 bytes
SHA-256: 5567156f02e0f86a5b9e7500f1db2bcdbd938899855d922f5b8eab3ef31bdf2b