Malicious PDF — malware analysis report

Static analysis result for SHA-256 44275057b91f24bc…

MALICIOUS

PDF

96.5 KB Created: 2021-07-18 17:51:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 15fcdff88f1e13d398da1dc54171df41 SHA-1: c7a7d37ee1a3016738bc112847f2776b9310a975 SHA-256: 44275057b91f24bc6c503b4bd1a5cbcfc9197f4d4c9cf9a7da1608ab5e888563
156 Risk Score

Malware Insights

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

The sample was identified as malicious by ML classifiers and ClamAV, flagging it as a phishing trojan. It functions as a link farm, with numerous URLs pointing to compromised CMS upload directories, suggesting an attempt to distribute further malicious content or phish users. The PDF structure and link farm characteristics indicate a deliberate effort to obscure the final destination and potentially exploit vulnerabilities in PDF viewers.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9929

Heuristics 6

  • 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 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://blog.crowdly.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d055b1acf0---mubifemijomek.pdf
    • https://betenrealestate.com/sites/default/files/file/xivonap.pdf
    • https://precisionautoandac.com/wp-content/plugins/super-forms/uploads/php/files/5d46d24422f2792ac8330c2546178ee7/lodopepobas.pdf
    • http://peusch.lu/userfiles/files/39722730305.pdf
    • https://www.denisonlandscaping.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c97df69b62---14893954130.pdf
    • http://wypelnienia.kratex.pl/wp-content/plugins/super-forms/uploads/php/files/be279b937b315082201cfd74f8d14b2c/59103674726.pdf
    • http://polymer-optix.de/userfiles/file/30434226829.pdf
    • https://hps-gruppe.com/wp-content/plugins/super-forms/uploads/php/files/lmtbvl8tpqhqhoc7b8tfpvqvhn/29166248107.pdf
    • http://wksystems.net/HotelEstimator/userfiles/file/65972412688.pdf
    • http://guides2alpes.fr/uploads/file/31318578266.pdf
    • https://directprocessors.com/wp-content/plugins/formcraft/file-upload/server/content/files/160980db69f7b3---81794634010.pdf
    • https://notofthisgalaxy.com/wp-content/plugins/super-forms/uploads/php/files/03rbtpar9d2l0quvaad3b23d36/73560095992.pdf
    • http://hpworld.hu/data/pic/Image/file/mezuzatiwuzug.pdf
    • https://digidatadecolombia.com/wp-content/plugins/super-forms/uploads/php/files/eb2b5dd51bca7aa41b816e78e51955e0/zapobiligakalasuzepila.pdf
    • https://avantkart.com/wp-content/plugins/super-forms/uploads/php/files/jpunsic1ui3to7ucr0tbh1ic35/nagubogufalo.pdf
    • http://netinflux.net/userfiles/file/rowune.pdf
    • http://champagne-marc-chauvet.com/images/files/gimesebavipalupula.pdf
    • http://anhbanglaw.com/userfiles/file/42365417293.pdf
    • http://renovator.cz/files/file/waxivivibes.pdf
    • https://ludifrance.fr/userfiles/file/76401579105.pdf
    • http://nano-vip.com/ckfinder/userfiles/files/kanirulofemete.pdf
    • https://playgametoday.ru/wp-content/plugins/super-forms/uploads/php/files/342f99dcba9f8f57cb21f4bdd50e7bea/58794919544.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=didnt+get+it
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010257.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10257 16792 bytes
font_01_sfnt_off00011a69.bin
b8c8fe4c51afcba3cd6e533575283ab1075d25f7ee1bfd0202734e1ce6d431f9
pdf-font-stream PDF embedded font (sfnt) at offset 0x11A69 17456 bytes
font_02_sfnt_off00014815.bin
d0e02ea597b059e12c640018e4c0b859d2fbe31b167f59dc9fd0dc6423c65742
pdf-font-stream PDF embedded font (sfnt) at offset 0x14815 16488 bytes
font_03_sfnt_off00015f01.bin
9ea208382d42650a2d0b76f2d500fe4e4cb33023c3b487d4689848af8141d9eb
pdf-font-stream PDF embedded font (sfnt) at offset 0x15F01 9828 bytes