Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c66257d50ef6be9…

MALICIOUS

PDF

82.6 KB Created: 2021-09-19 05:00:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b96b91ad4b91db09d10ffbf8e2294882 SHA-1: 26153c5c46f9e8f5fe919d943cdca228f157b32d SHA-256: 3c66257d50ef6be98d9e2c029ebd224a14a0de98bb8ba9c552edb9288dd3d23b
236 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external resources, many of which are hosted on disposable domains or compromised WordPress sites, indicating a link farm designed to distribute malicious content. The presence of a 'SE_PASSWORD_ARCHIVE_LURE' heuristic suggests the document may instruct users to open a password-protected archive, a common tactic to bypass gateway security. ClamAV detection and ML classification further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • Password-protected archive handoff high SE_PASSWORD_ARCHIVE_LURE
    Document gives password instructions for an archive or attachment — often used to keep payloads encrypted until after gateway scanning
  • 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://inwebjor.ru/uplcv?utm_term=how+to+remove+android+pin+lock
    • https://parvazyab.com/basefile/api203/files/19461185887.pdf
    • https://crbz.ru/userfiles/file/85194520628.pdf
    • http://mikailang.net/userfiles/file/20210919072911_608962106.pdf
    • https://childrencareandliteracysociety.org/userfiles/files/vukadupajofibijixane.pdf
    • http://olech-rzeszow.pl/userfiles/file/radopebed.pdf
    • http://tksvolga.ru/userfiles/file/22004321962.pdf
    • https://kindliving.org/wp-content/plugins/super-forms/uploads/php/files/tmp/riwowugilipitabatux.pdf
    • https://cowichanseniors.ca/userfiles/file/38328986879.pdf
    • https://maggievanostrand.com/uploads/media/file/femewafaluken.pdf
    • http://thibangoto.com/app/webroot/uploads/files/liwifiwujepezapera.pdf
    • https://esterkins.de/ckfinder/userfiles/files/jipapewozipuzanebibotuxov.pdf
    • http://predit.ru/admin/ckfinder/userfiles/files/9681331671.pdf
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1612eedcd00f8a---16856356415.pdf
    • https://maturana.cl/upload/file/49129599038.pdf
    • http://volker-issmer.de/userfiles/file/78685462411.pdf
    • http://gndpta.eu/news_objects/files/bekofakipusafaxivumeju.pdf
    • http://www.propper-droppers.nl/files/file/xuzetedojoni.pdf
    • https://cradlegold.com/wp-content/plugins/super-forms/uploads/php/files/5l6meeeus86h51io67ms8j0i8f/bivonetidaf.pdf
    • http://okna-stv.ru/userfiles/files/73435033978.pdf
    • http://htwy.com/upload/file/73847796277.pdf
    • http://vector-food.com/userfiles/file/74514138904.pdf
    • http://c2ctrading.org/cms_upload/files/17702924575.pdf
    • http://massageindex.nl/images/uploads/labigitowotem.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dd4f.bin
467535cea9feaa5b028dabb035179b337c04c2a41f39deada9813cf2ff3029a8
pdf-font-stream PDF embedded font (sfnt) at offset 0xDD4F 18028 bytes
font_01_sfnt_off00010bfb.bin
cbb3a0866d73441b1c20c06bf63ae8e818d9238576da9899d449fc71a85598b4
pdf-font-stream PDF embedded font (sfnt) at offset 0x10BFB 10744 bytes
font_02_sfnt_off000124a6.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x124A6 16792 bytes