Malicious PDF — malware analysis report

Static analysis result for SHA-256 59cac536debcc149…

MALICIOUS

PDF

46.1 KB Created: 2020-07-28 12:39:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 21fda7667702b8cb32ae1c90723cf832 SHA-1: b1e1dde14ffaf43b7ab953529c8652ad0fe38857 SHA-256: 59cac536debcc149470800674135491549b816ffbfcaf915313777aa6d12bcd1
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by multiple critical heuristics for containing malicious redirector links and a link farm. The ML classifier also strongly indicated maliciousness. The document body, though heavily obfuscated, appears to contain text related to 'free printable 6th grade vocabulary worksheets', likely a lure to disguise the malicious intent of the embedded links. The primary malicious IOC is the redirector URL, which is designed to lead users to further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://ttraff.cc/pify?keyword=free+printable+6th+grade+vocabulary+worksheets
    • http://files.lornasredskygeckos.com/uploads/1/3/1/3/131380078/5030752.pdf
    • http://files.theprideoflouisville.com/uploads/1/3/0/7/130740149/tadojop.pdf
    • http://files.mysticpointwatersports.com/uploads/1/3/0/7/130776401/lijebapamifupu-bifupibusej-kekexagererubiz.pdf
    • http://files.mulberryumc.com/uploads/1/3/2/7/132710783/ralolojik.pdf
    • http://files.tomcondotta.com/uploads/1/3/1/0/131070792/c08bb10cec19838.pdf
    • https://cdn.shopify.com/s/files/1/0429/4855/9004/files/50151939149.pdf
    • https://cdn.shopify.com/s/files/1/0429/1405/4300/files/78142434909.pdf
    • https://cdn.shopify.com/s/files/1/0434/6796/4580/files/80343279017.pdf
    • https://cdn.shopify.com/s/files/1/0440/7679/4021/files/muvok.pdf
    • https://cdn.shopify.com/s/files/1/0428/0814/8127/files/67976560044.pdf
    • https://cdn.shopify.com/s/files/1/0428/2286/0966/files/xuzukomejilazefoxabonaj.pdf
    • https://cdn.shopify.com/s/files/1/0433/4695/2351/files/fasegiga.pdf
    • https://cdn.shopify.com/s/files/1/0434/1583/0695/files/vipumiwetug.pdf
    • https://cdn.shopify.com/s/files/1/0432/2597/2904/files/92525413020.pdf
    • https://cdn.shopify.com/s/files/1/0430/0177/4233/files/85964981827.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/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00007528.bin
8119cec9f265d61755c546e3d2814aa896e61db64dc619f8a246a0dd17505ef6
pdf-font-stream PDF embedded font (sfnt) at offset 0x7528 5784 bytes
font_01_sfnt_off000088dc.bin
5000947c577314208a0af8ccc63cd56785c3c6e1cebc88d9dfac05adc60a77e2
pdf-font-stream PDF embedded font (sfnt) at offset 0x88DC 9896 bytes