Malicious PDF — malware analysis report

Static analysis result for SHA-256 37da31f88500c74f…

MALICIOUS

PDF

88.6 KB Created: 2021-09-17 03:53:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b4a86b2b6778e26d731531b1a5d85fa4 SHA-1: 8abe3044b4ca8e68f6f883db89bb647a17b2c0a7 SHA-256: 37da31f88500c74f9784dbab6c6f47df00700dd0fcae32169cd8c55deb780786
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to external websites, some of which are hosted on compromised CMS upload storage or disposable hosting, suggesting a phishing or malware distribution scheme. The presence of embedded URLs and the PDF structure point towards an attempt to redirect users to malicious content, likely involving JavaScript execution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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://lyubomiradineva.com/files/file/33162869903.pdf
    • https://e-ceramika.pl/userfiles/file/51053675270.pdf
    • https://indiachristian.org/uploads/files/sigof.pdf
    • http://quaisetoiles.fr/img_pages/file/29354190764.pdf
    • https://bawwabatrizq.com/userfiles/file/solexefuzesopufike.pdf
    • https://www.hadlowsecurityshutters.com/wp-content/plugins/super-forms/uploads/php/files/c7712580df21873e152a7b1e63f21cbe/39546493789.pdf
    • https://www.shopveriamici.com/wp-content/plugins/super-forms/uploads/php/files/5ar34oc0l522rkm7iu9ppop89k/dojazexodefejatuj.pdf
    • http://trip-sale.ru/userfiles/file/wewosujijijipisimojofebo.pdf
    • https://www.huaikrachaohospital.go.th/assets/global/lib/ckfinder/userfiles/files/38383419891.pdf
    • http://kingkady.cn/uploadfile/files/sedokemerulimeretasur.pdf
    • http://gotoippc.com/ckfinder/userfiles/files/lujod.pdf
    • http://www.radiopopiatej.com/wp-content/plugins/formcraft/file-upload/server/content/files/161408e7fceab8---91431587948.pdf
    • https://www.lorenzofranzone.it/wp-content/plugins/super-forms/uploads/php/files/9b41d8d27877715a31eb759ec85d1553/30892884641.pdf
    • http://pointerboards.com/uploads/admin/files/naxenuze.pdf
    • https://mt-creativestudio.com/ckfinder/userfiles/files/vekojafalokakivovudirude.pdf
    • http://www.reeder.ee/files/filemanager/zonapalajebenepezubodid.pdf
    • http://185.33.116.142/~bbyacht01/upload/files/30843668702.pdf
    • http://strandedtattoo.net/file/4907563278.pdf
    • http://kondicionery-vidnoe.ru/upload_picture/file/19837582101.pdf
    • http://richmore.kr/uploadfile/fckeditor/file/takawanegagubowa.pdf
    • http://aaaexpressac.com/userfiles/file/99332441709.pdf
    • http://szerecsen.hu/editor_up/luwexomutaxefawopi.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130433660903---62564760331.pdf
    • http://poledance-chrudim.cz/files/file/37777001229.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=american+ways+4th+edition+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_off0000f327.bin
475ef8528d2b388ccaafdac4415f1f55c078ef41b9c0bee901003913958cd427
pdf-font-stream PDF embedded font (sfnt) at offset 0xF327 18644 bytes
font_01_sfnt_off000123aa.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x123AA 16792 bytes
font_02_sfnt_off00013bc1.bin
1326be427356b60a20b314f051cc7adae6f74c9fa0a75ec5b912dab8a511d10a
pdf-font-stream PDF embedded font (sfnt) at offset 0x13BC1 11100 bytes