Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf6421d251c53a74…

MALICIOUS

PDF

66.9 KB Created: 2021-09-18 17:18:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: ef5fc15974605a324647df989ec721af SHA-1: ee9bc63c980c252d3da498141c3db4232e3764a2 SHA-256: cf6421d251c53a74b6b60f1682f5cbbc14240ec306aec9162b184c49f4c71d15
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF employs an image lure, a common phishing tactic, to disguise clickable links. Multiple heuristics indicate it's part of a link farm hosted on potentially compromised or disposable domains, suggesting an attempt to distribute malicious content or redirect users to phishing sites. ClamAV detection and ML classification strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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
  • Image-only document with action trigger (screenshot lure) medium PDF_IMAGE_LURE
    PDF has 1 image(s), only 0 text block(s), carries a click-outward action, and is only 66 KB — typical shape of a phishing lure where a full-page screenshot hides a clickable button that launches or submits to an attacker URL.
  • 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://minipit.com/data/files/37305960449.pdf In PDF document text
    • http://duetsepolno.pl/userfiles/file/rijametotuxenexoti.pdfIn PDF document text
    • http://sjhtractor.com/d/files/dazowanaravog.pdfIn PDF document text
    • https://centrorevisionimonregalese.it/file/sojaguba.pdfIn PDF document text
    • http://jjw-led.com/userfiles/file/simudawadidovasabin.pdfIn PDF document text
    • https://atvatextile.com/upload/ckfinder/files/fifabexigebisopop.pdfIn PDF document text
    • http://xn----7sbqwxdbhblh2h.xn--p1ai/data/file/59257919113.pdfIn PDF document text
    • http://catherine-massage.com/ckfinder/userfiles/files/34494729831.pdfIn PDF document text
    • https://luatsubienhoa.com/upload/ck/files/jedojuboworiwuroruxafiv.pdfIn PDF document text
    • http://yurisolomko.com/userfiles/file/44277377641.pdfIn PDF document text
    • https://ags-car.com/upload/files/16480505016.pdfIn PDF document text
    • https://www.penyembuhanholistikreiki.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133c7358df3e---49468963429.pdfIn PDF document text
    • http://www.nachtruhe.info/up/files/feninidesimadov.pdfIn PDF document text
    • http://wskinbody.com/data/boardData/files/63359899917.pdfIn PDF document text
    • http://jongauger.com/ckfinder/userfiles/files/3363893499.pdfIn PDF document text
    • http://shengyaweb.com/uploadfile/file/2021090810141840.pdfIn PDF document text
    • http://inspirationallabels.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16131d045a1df2---mipexakafavomu.pdfIn PDF document text
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/1612f451ace805---xatowenabokibibuzefaka.pdfIn PDF document text
    • http://halongbaycruises.org/upload/files/xekesigej.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=net+tv+on+firestickPDF 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_off0000acb8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xACB8 13960 bytes
SHA-256: a4224a08626fdc7f7c2a73a608360afc72cd8cba7f79f794120f5cf357f2309d
font_01_sfnt_off0000cf3b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF3B 10256 bytes
SHA-256: 9c4764ce3f23a51807a713b3854b126bc855c7619a6757810c5d945ee241fbfd
font_02_sfnt_off0000e67f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE67F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1