Malicious PDF — malware analysis report

Static analysis result for SHA-256 f54f88a53b0e8fc3…

MALICIOUS

PDF

81.0 KB Created: 2021-06-14 03:19:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: afc6fb0689d743053cf91cceebba3289 SHA-1: a9dba873b43332420929efd267efd7cdf6fd5c5c SHA-256: f54f88a53b0e8fc3fa2c1be27a549b6ae79ee5cd3d9a5db4c5095a4ed996e075
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links to compromised WordPress sites and disposable hosting, suggesting a phishing or malware distribution campaign. The document body, though heavily obfuscated, appears to be a lure related to 'reading exercises', which is a common tactic for phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://laborke.ru/uplcv?utm_term=simple+past+tense+reading+exercises
    • http://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160a173bcb4f5d---55156130571.pdf
    • https://asaptransfers.co.uk/wp-content/plugins/super-forms/uploads/php/files/059dnco0orpsfruqdrthc6vcv3/69821841013.pdf
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160b546a860556---13745561913.pdf
    • http://allamericannursing.com/userfiles/file/xisowere.pdf
    • http://fiumaradelsossio.it/userfiles/files/toxezokarem.pdf
    • https://higher-reason.com/wp-content/plugins/super-forms/uploads/php/files/qb74ji8tantq6mt4oc1rottck1/xibigolu.pdf
    • http://halvani.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e5eae7369b---61499462984.pdf
    • http://sattosushi.com/uploads/files/kizuzaledasexebivibasotaf.pdf
    • https://www.numberoneporthill.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1609ee74942696---kupemegite.pdf
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606f33e427ea4---bozotubilabetikifowiwel.pdf
    • https://prairieroseclothiers.com/FCKeditor/file/42690886577.pdf
    • http://driscollandgibson.com/images/edit_images/file/duwibunujis.pdf
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/160b5802c3223a---38063675402.pdf
    • https://provisionsinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aed962f2a30---mupisix.pdf
    • https://la-klamm.org/Files/files/80433684265.pdf
    • https://diphong.com/uploads/fowot.pdf
    • https://www.alarisusallc.com/wp-content/plugins/super-forms/uploads/php/files/32167a64eea9e2290d62a75bb9240d02/90749510325.pdf
    • https://www.alpha-dynamics.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1607b2171c9773---36281067252.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.daltonmaag.com/
    • 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://scripts.sil.org/OFL

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ef43.bin
d7d7e5fe73ff9afec95b5c6fa66e828589aafbb320484f290145d34fbfda3785
pdf-font-stream PDF embedded font (sfnt) at offset 0xEF43 5240 bytes
font_01_sfnt_off000100ee.bin
cbdbc8b5ac4d134ee0c0dbbee114b50a7a7f447a523fd7675ed06cb2948e53a3
pdf-font-stream PDF embedded font (sfnt) at offset 0x100EE 11136 bytes
font_02_sfnt_off0001268a.bin
1158d95dac44631f497756703988ba3645251422e7ff0015d3fca430225e7c3e
pdf-font-stream PDF embedded font (sfnt) at offset 0x1268A 4324 bytes