Malicious PDF — malware analysis report

Static analysis result for SHA-256 500f518c872b170a…

MALICIOUS

PDF

80.6 KB Created: 2021-09-17 14:35:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7b4d6fbbe779f16bbe552889978bb1c7 SHA-1: d3a74d260e7906007dc7b244c9a7c16bfa5ca6f9 SHA-256: 500f518c872b170a1ca34f590620aae2e7376fad56fca220809cfd4097a95812
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous external links, many pointing to compromised WordPress upload directories or disposable hosting, suggesting a phishing or malware distribution scheme. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content but serving as a vessel for these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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 https://irlanc.ru/uplcv?utm_term=instagram+full+size+picture+viewer
    • https://hotelmitrutarija.com/uploaded/files/74137336327.pdf
    • https://szelvedojavitasmiskolc.hu/files/files/69020755791.pdf
    • https://gamaconsultores.cl/upload/file/piviwekafikilaligi.pdf
    • https://trouver-une-ssii.com/img/pics/files/nevipugigoz.pdf
    • http://webinaris.blog/ckfinder/userfiles/publics/files/kogusunexezegozokebif.pdf
    • http://lj-group.cn/upload/files/teven.pdf
    • http://polipack.ru/content/file/61009533654.pdf
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1613033d72905a---52710373591.pdf
    • http://pyhunlian.com/uploadfile/file/famatuvuzi.pdf
    • https://kaptenhoki.com/contents/files/lipapon.pdf
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139ab5ce8acc---xatuloxuduxaledawavig.pdf
    • http://tianlanip.com/filespath/files/20210913010444.pdf
    • http://feldbach-tourismus.at/files/7752011148.pdf
    • https://sapporomn.com/userfiles/files/82955857483.pdf
    • https://francemonde.news/UserFiles/file/22383150367.pdf
    • http://thuocamakong.net/userfiles/image/file/zavenoz.pdf
    • http://occahomesearch.com/userfiles/files/56817783384.pdf
    • https://fa-vietnam.com/webroot/img/files/24139754180.pdf
    • https://mountainbrookbuilders.com/home/mountain/public_html/ckfinder/userfiles/files/44268345207.pdf
    • https://soalmatematik.com/userfiles/file/vekopuwiwulagenugu.pdf
    • http://bernendorf.ru/userfiles/file/xububaxomugar.pdf
    • http://hiroi-es.info/yamituki-n/uploads/files/gaxemikajojasiforijibokev.pdf
    • https://elicopter-de-inchiriat.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161417d60d7d34---60721991334.pdf
    • http://dj-maily.com/uploads/pages/files/98455517794.pdf
    • http://ephtour.com/FileData/ckfinder/files/20210913_C7DC89F577BB7DC4.pdf
    • http://expertcomptablecourreges.fr/michel_courreges/userfiles/file/pamufonotifokuwodarut.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_off0000cb20.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCB20 16792 bytes
font_01_sfnt_off0000e332.bin
1043042e7bef82fde055f50ff7010ce87f68537ac66eca92c5e88618469a40ce
pdf-font-stream PDF embedded font (sfnt) at offset 0xE332 21304 bytes
font_02_sfnt_off00011b1f.bin
84b9a7b2357536ad3d6108c435574c0df2c2a27d9a096bafc627e252af62933a
pdf-font-stream PDF embedded font (sfnt) at offset 0x11B1F 10968 bytes